Connecting-rod for pneumatic drills.



A. LVEDAHL.

CQNNECTING non Fon PNEUMATIC DRlLLs.

APPLICATION FILED SEPT. 30, 1915.

Patenfd De@ l2, w36.

2 SHEETS-SHEET l.

'A. LEVEDAHL.

CONNECTING ROD FOR PNEUMATIC DRILLS.

APPLICATION FILED SEPT. 30. I9I5.

Patented Dec. 12,: 1911.6.

2 SHEETS-SHEET 2.

Inl/@7115?" flafel Lez/@dam rr is;

AXEL LnvnnAHL, OF AURORA, ILLINOis," AssIGNOn 'ro AURORA AUTOMATIC MACHINERY COMPANY, or CHICAGO, ILLINOIS, A CORPORATION or DELA- WARE.

CONNECTING-ROD FOR. PNEUMATIC DRILLS.

Application filed September 30,1915. Serial No. 53,456.

To all whom t may concern Be it known that I, AXEL LEVEDAIIL, a citizen of the United States, andav resident o-f Aurora, in theco-unty of Kane and State of Illinois, have invented certain new and useful Improvements in Connecting-Rods for-Pneumatic Drills; and Ido hereby declare that the following is afull, clear and exact description thereof, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specication.

This invention relates to improvements in the construction of connecting rods and associated parts, and more particularly to the construction of connecting rods and parts for use in pi'sto-n driven pneumatic drills and like tools.

ln the usual construction of tools of the class described the power is transmitted to the tool by the transformation of reciprofv cating motion into rotary motion by means of pistons, usually single acting, which are actuated by the admission of air pressureinto cylinders carrying said pistons, the latter being connected to ya crank shaft by the usual connecting rod. A common construc- .tion is to. provide an arrangement of the cylinders whereby the same are located in the same plane and displaced at an angle to each other, .preferably 90, the connecting rod of each piston of said cylinders being connected at a single point on the crank. It is to this particular type of tool that my invention has reference, although its application is equally' well suited for any form of tool or mechanism having reciprocating pistons. l. y

Tools of this descriptionare ordinarily run or operated at extremely high speeds, are subjected to rough handling, and Often misused by the absence of lubrication in sufcient amounts. As a result of these conditions, the moving parts undergo severe usage and are required to withstand a considerable degreeof vibration. rlFhe connecting rods in the. usual form 'of tool are made from solidforgings, which are connected at their ends to the piston and crank by means of hingepins, bolts, screws, and the like. By reason of the extremely high speeds at which such tools are operated andthe vibrations to which the connecting rods are subjected, as lwell as the extreme heat caused by the neglect of lubrication, the connecting rods,

bearings and parts of said rods have been found to admit of considerable relative movement, which in time effects .such a degree of wear as to render the parts incapable of smooth and proper movement, and greatly increasing the liability of breakage thereof.

Specification of Letters Patent. Ptggntd Dm), t2, jlgjl,

Among the objects of my invention is to provide a construction for connecting rods and associated parts that will successfully remove the difficulties hereinbefore set forth, and otherwise improve the operation and efficiency of air operated tools and the like.

In accomplishing the desired results, I propose primarily to form the connecting rod from a single piece of metal, the same being formed from a blank cut or stamped to the desired shape or contour from sheet metal, preferably cold rolled sheet steel. The blank thus formed is then bent at its centra-l point upon itself, those portions of the blank intermediate the ends of the rod vbeing folded in Contact with each other and forming the shank of the rod of two thicknesses of sheet metal identical in contour. The end portions of the folded blank are likewise identical in form and are bent cylindric to provide a hollow cross pin or split bearing, as the case may be. To connect the connecting rod thus formed to the crank and to the piston, ll, provide clamp members or straps, the same oeing formed from a flat blank made from sheet metal such as steel, said straps being provided with substantially cylindric portions which encircle the cross p-ins or split bearings of the rod and are clamped by means of bolts or the like to the shank or rod. c

As a further feature of my invention, and in connection with the form of tool embodying the angularly arranged cylinders as before mentioned, the split bearing of one rod is preferably made of sullicient length so that it forms a centralbearing for the split bearing of the other connecting rod, the bearing or sleeve of the latter being clamped about or encircling the split bearing of the first mentioned rod.

rlhe. features of myl invention will be more read-ily understood as l proceed with the description of the invention and in connection with the accompanying drawings, wherein the parts are shown by figures as v follows:

Figure l is a view in side elevation of two A ranged at an angle to each other and each on line 4-4 of Fig. 2; Fig.l 5 is a t-op ,planA View of ay sheet Imetal blank from which one of the connecting `rods is formed; Fig. 6 is a perspective view of a lconnecting vrod formed from the'blank shown Vin Fig. 5; Fig. 7 is a top plan viewof a sheet metal blank from which another connecting rod is formed; Fig. 8`is"`a perspective View of the connecting rod formed from the blank shown in Fim 7; Fig. 9 is atop plan view vof the fla-tl lblank-from which -t'he clamp member or strap yused with the connecting rodshownY in' Fig. 8 is formed; Fig. 10 is a perspective view of the clamp member or lstrap formed from the blank shown in Fig.

9; Fig. 11 is a top plan view of the flat blank from which the clamp member or strap used with the connecting rod shown in Fig. 6 is formed; Fig. 12 is a perspective view of the 'clamp member or strap formed from the blank shown in Fig. 11; and Fig. 13 is atop plan View of the sheet metal blank from which is formed the strap for connecting the cross pin of the connecting rod to the piston.

Referring to the drawings, wherein is set forth in detail the construction for connectingVA rods and associated parts embodying the features of my invention, two'pistons 15 and 16 are shown (Figs. 1, 2, and 3) adapted for reciprocating movement in cylinders of a pneumatic tool (not shown) located inthe same plane and arranged at an angle of l90 to each other. l atively connected with the 'same or a common crank-shaft, pin, or the like 17 by connecting rods 1 8 and 19, respectively.

The connecting rod 18, which connects the `piston 16 with said crank-shaft 17, is

formed from a' flat4 blank 20 cut or stamped from sheet metal, preferably cold rolled steel, in the form shown in Fig. 5, and as illustrated, comprises a rectangular central portion 21 and two larger portions 22, 23 identical in form and in-size and disposed on opposite sides of and spaced atan equal distance lfrom said central portion 21. Said i rectangular end portions 22, 23 are integral with and connected to said central portion 21 by longitudinal portions 24, 25 extending laterally from opposite sides of said central portion 21, said longitudinal tions 24, 25 being equal in length and wldth and, as shown, laterally narrower than either the central or end portions of the blank. Each end portion 22, 23 is provided within its margins with a rectangular open- Said pistons are each oper-` sponding positions in-said end portion 22,

23. The connecting rod 18 is formed from said blank 20 by bending. said blank at its central port'ion upon itself, so .that the longitudinal portions 24, 25. and the end portions 22, 23 are brought against and atwise into contact with each other with the openings 26, 27 of the latter in registering relation. In the operation of forming the Connecting rod, the central portion 21 is bent cylindric in shape, as shown in Fig. 6, the opposed margins 21, 21b of said central portion being disposed in abutting relation, when the same is given its cylindric form. The central portion thusformed constitutes a hollow cylindric cross-pin at the piston end of the rod, adapted to befpivotally attached to the piston, as will hereinafter be set forth.` The opposite ends of the rod,

lconsisting of the end portions 22 and23,

which are brought flatwise in to contact with each other by the bending of the blank, are

each bent, by means of. a mandrel, intoa serting the crank between them, the resiliency of the members permitting the spreading of the parts as well as serving to maintain the parts 28 and 29 in close contact with the crank. In order to clamp the members 28, 29 of the split bearing about the crankshaft 17 and prevent said members from spreading apart or moving laterally relatively to each other, when the rod is subjected to vibrations, a 'clamp member or strap 3() is provided (Fig. 12), the same being formed from a blank 31, which is Stamped or cut from sheet metal, in the form of' a flat plate, asv shown in Fig. 11. As illustrated, said blank 31 comprises two Hat, substantially parallel, laterally spaced, longitudinal members 32, 33 equal in length and connected with each other at the ends thereof by flat, transversely parallel, end members 34, 35, the latter being equal in length -members 28, 29 of the split bearing and inand integral with the longltudinal members To form the complete clamp member or .strap 30, the blank 31 is bent, by suitable ymaintained flat and in the bending of the blank are brought opposite each other in parallel, relation, the same being separated by a space, as shown in Fig. 12. The strap 30 is preferably'made from rather heavyv sheet material, so as to give rigidity and strength to the parts, although the thickness of the metal throughout5 the cylindric portions 36 and 37 is reduced by boring out the inner surfaces thereof, thereby affording a degree of elasticity necessary in applying the' strap, as will presently appear. rll`he clamp member or strap 30 thus formed is applied to the cranklend of theconnecting rod 18 for the purpose of securing the members 28, 29 of the split bearing of the connecting rod tightly about the crank-shaft, this being accomplished by springing or spreading apart the transverse end portions 34, of said clamp member and forcing the same over' the split bearing of the rod 18 until the cylindric parts 36, 37 encircle the split bearing of the rod. By reducing the thickness of the cylindric parts 36, 37 in the manner before suggested, the clamp member is rendered more flexible, thereby permitting the clamp member to be forced over the split bearing of the rod 18. When the clamp member or strap 30 is applied, the same occupies the position shown in Figs. 1 and 4, with the cylindric parts 36, 37 inv contact with and encircling the members 2 8, 29 of the split bearing of the rod 18, the contacting apertured parts of the rod 18 being interposed between and overlapped by the parts 38, 39 andthe end members 34, 35 of said clamp member. As shown, the openings formed between the parts 38, 39 and the transverse end portions 34, 35 of said clamp memberV register with the apertures 26, 27 in the rod 18.` rllhe clamp member 30 is secured to said rod 18 by screws 40, 41, or other suitable connecting members, extend- `ing through registering holes 42 and 43 formed in the connecting rod 18 and strap 30, respectively, said holes being preferably formed at the time the blanks are cut or stamped. The cylindric portions 36, 37 of the strap being spaced apart, it is to be noted that the same embrace only the end portions of the split 4bearings of the rod 18, the portion of the split bearingextending between said members 36, 37 of said clamp member 30 being exposed and providing a center bearing for the other connecting rod 19, as will hereinafter be pointed out.

The connecting rod 19, shown in Fig. 1 as connected with the piston 15, is formed in the same manner as the connecting rod 18, just described, namely, from a sheet metal blank 44 having the form shown in Figi 7. This rod is provided at its-ends with cylindric portions as before, namely, a central portion 45-constituting the cross-pin having abutting marginsv45a and 45b and two end -portions 46 and 47 adapted to be -,brought into contact, and the end marginal portionsshaped semi-cylindric to provide a split bearing. The connecting rod -19 differsv from the connecting rod 186m the formation of the crank end thereof, in that the 'end portions are substantially narrower and somewhat greater in length, although the shank portions 48 and 49 are identical in form as in said previously described rod 18, and but slightly narrower in width than the end portions 46 and 47. The end portions 46 and 47 are bent into cylindric form as before, with their end margins 46a and 47a brought into abutting relation, thus forming a split bearing, as shown in Fig. 8. The width of this bearing is substantially equal to the width of the apertures 26 and 27 of the connecting rod 18 and likewise equal to the distance between the adjacent margins of the cylindric portions 36 and .37 of the strap 30. The inside diameter of the split bearing is greater than that of the corresponding bearing of the rod 18; in fact, it

is substantially equal to the outside diameter Vof the split bearing of said connecting rod 18. The reason for this construction will be manifest, when it is pointed out that the Split bearing-of the rod 19 embraces the split bearing of the rod18 and engages that portion of the latter between the end portions thereof, ,as is clearly shown in Fig. 2. The

connecting rod 19 is connected to the crank 17 by spreading the semi-cylindric parts of the split lbearing apart and passing them around the central portion of the bearing of the rod 18, the latter thus serving as a bearing for the crank of the rod 19. In this manner the split bearing of the rod 19 surrounds that portion of the bearing of the rod 18 intermediate the cylindric portions 36, 37 of the strap 30, one part .thereof extending through the apertures 26 and 27 of the rod 18.

rllhe crank end of the rod being applied in the manner stated, it is firmly clamped by means of a strap 52, (Fig. 10), which is formed from a blank 53 (Fig. 9), bent to provide a substantially cylindric central portiony 54 and two parallel end portions 55 and 56. The strap 52 has a single cylindric portion, which is of greater diameter than the cylindric portion of the strap 30, but, as before, has its inner surface bored out to provide areduced thickness of metal in order to afford the degree of flexibility required to apply it to the connecting rod. The .strap 52 is mounted in position by spreading the ends 55, 56 thereof apart and Vinserting the split bearing of the rod 19 into the' cylindric portions thereof, said bearing being completely .embraced by said V str ap. lThefend portions 55 and 56 of the strap 52 4are' brought into contactwith and against the adjacent portions ofthe shank of thel connecting rod, v'and are' secured thereto by means 'of screws,58 and 59, which extend through registering holes 50 and 57 formed in the connecting rod-19 and endportions of the strap 52, respectively, said holes being preferablyv provided when the blanks are formed. It is to. be noted that the cylindric portion of the strap 52 passes through the apertures'26 and 27 of the rod 18, and occupies a position intermediate the cylindric portions "of the strap 30 of the other rod 18. In this manner the connecting rod 19 is securely held in bearing engagement with'theoutensurface of the bearing of the 'rod 18, both rods being, in fact, connected to the crank 17 at substantially the connecting rods.

The connecting rods 18`and 19 are connected at the piston ends thereof to each of thei rassociated pistons 15 and 1 6, respectively, by straps or yokes 60, pneferably made as follows: Each yoke is formed from a sheet metal blank 66 (Fig.13) having curvilinear end margins and provided at its central portion 67 with a rectangular aperture 68. The central portion of the blank is bent to provide a semi-cylindric yoke portion extending transversely from either side of the central aperture 68. Each strap is preferably cut into two parts along a longitudinal `central line d .(Fig. 18), each part constituting a strap adapted to engage an end portion of a cross-pin, as shown in Fig. 2, the same being journaled in a bearing block having a concave seat and extending throughout the length of the crosspin and beyond the ends thereof. The yoke portion of each strap embraces the bearing block, together with the ends of the crosspin, the remaining portion of the strap constitutingl Hanges 62, which fit within the bottom of the piston and are attached to the v cylinder head by means of rivets 64 extending vthrough holes formed in said flanges of the strap and the head of said piston. By this construction, the impact of the air against the piston is received by the bearing block 65 and. transmitted to the connecting rod through the cross-pin which vis journaled to said block, thereby relieving the straps of any strain Aduring the power stroke as wouldtend to loosen the rivets by which said straps are secured to the piston and permit breakage. This is apparent since the pistons are single acting, and hence power is applied only during one stroke of the piston, namely, in the direction which the piston would be moved by the pressure of the air acting upon the outer surface of the piston head.

It is to be noted that the. cross-pins are slightly less in length than the bearing blocks 65, and also that the'space between the yokes of the straps is slightly greater than the width" ofthe shank portions of the connecting rods. This arrangement permits a degree of relative lateral movement between the piston and the connecting rod, thus admitting of a slight adjustment between these members in case any inaccuracy occurs in the boring of the cylinders, or a slight deviation of the cylinders from a common plane.

' The advantages resulting in the applica- `tion of this construction for connecting rods and associated parts thereofto pneumatic tools are numerous, among which a few may 'be mentioned at this time. One of the features already pointed out is the formation of the connecting rod from a single piece of metal. By this construction a rigid and integral unit is provided which is connecteddirectly to the crank by means of the bearing formed integral with the rod, and to the piston by a strap which acts to journal a cross-pin also integral with the rod. This results in the elimination of several members. connected together by hinge-pins, bolts, screws, and the like, which in time are liable to work loose, thereby permitting a degree of play that would increasethe wear and otherwise materially affect the operation of the tool.

A further advantage is to be noted in the manner in which the rods are' journaled upon the crank. By providing a split bearing integral with connecting rods, it is possible to provide a full journal or bearing surface for one of the rods, and at the sameI time permit the use of a strap to securely hold the parts of the bearing together, and at the same time obtain sufiicient space oii said bearing to permit it to act as a bearing for the other rod. In this manner one rod is provided with a journal or bearing surface suiiicient to effect the proper transmission of power from both pistons to the crank.

A further advantage to be secured, and one that has already suggested itself, is the lightness and cheapness of construction that can be obtained by the exclusive use of sheet metal in the manufacture of the parts. The stamping of the parts from sheet metal by the use of dies is admittedly the least expensive method of machine work, this fact being of vital importance, in that it reduces the cost of production to a large degree. In addition to this advantage, it is possible to use sheet metal that is cold rolled,

contain the crank.

Lacasse l rod is journaled upon the bearing of the other rod, thus requiring but a single bearing on the crank, but from the fact that the use of screws, bolts, or lugs at the ends of the rods is entirely eliminated by the use of the straps, which merely surround the split bearings at the crank ends and have no parts projectingv beyond their surfaces as would necessitatethe provision. of sufficient space to permit their free movement. f

The last advantage to be mentioned concerns the simple and effective method that can be employed in securing the piston to the connecting rod. rlChe use of the conca-ve bearing block and the straps riveted to the piston head and provided with the yokes, which act tojournal the cross-pins in said' bearing blocks, makes it possible to construct the piston in a comparatively inexpensive manner, since the head need not be thicker than the Walls, for the reason that no portion orconnecting parts of the rod extend through the piston head, thereby requiring a suflicient thickness of metal to properly connect the piston and the connecting rod together. For this reason it is even possibleto form the pistons from sheet metal as Well as the connecting `rods and straps, thereby securing tvheadvantages before pointed out with respect to said connecting rods and straps. lln addition tothe possibility of the almost exclusive use of sheet metal and die' Work in attaching the piston to the connecting rods, a further advantage results from the fact that lno part of the connecting rodextends through the head of the piston, namely, that when the pistons and connecting rods are assembled,"

there is no opportunity for lleakage through the bottom of the piston, since there is no part of the connectingrod that extends through the piston head that ma'y become loosened and admit the passage of air, Which would manifestly reduce the efficiency of the tool.

The details of construction'of the parts embodying the features of my invention may -be variously modified Without departing from the spirit of my invention, and for that reason ll do not Wish to be limited to the particular construction herein described and illustrated, except in so far as specilically pointed out in the appended claims. li claim as my invention:

l.' The combination with pistons and a journaled on said crank, and the bearing of crank, of connecting rods joining said pistons with said crank, said rods being formed from blanks cut from sheet metal and folded to provide a double thickness of metal throughout the length of the rods, and the free ends of said blanks being bent semicylindric in form to provide a tubular bearing at one end of each of said rods, the bearing of one of said rods being adapted to be the other of said rods beingadapted to be ]ournaled on the bearing of said first mentloned rod, and means for pivotally connect- .ing the opposite ends of said rods with said pistons.

2. rlhe combination with cylinders, vpistons in said cylinders, and a crank, of connecting rods joining said pistons with' said crank, said rods being formed from blanks cut from sheet metal and folded transversely at their central portions to provide a double thickness of metal throughout their lengths, each of said blanks being provided with enlarged end portions adapted to be bent semicyllndric in form to provide a tubular split bearing at one end of each of said rods, the bearing of one of.said rods being adapted to be j ournaled on said crank, and the bearing of the other of said rods being adapted to be journaledv on the bearing of the said first mentioned rod, and means for pivotally connecting the opposite ends-of said rods with said pistons.

3. lin a device of the character described, the combination With pistons mounted in 100 cylinders arranged at an angle to each other, and a crank, of connecting' rods connecting said crank and pistons and formed from blanks cut from sheet metal, each of said blanks being folded upon itself to provide 105 a double thickness of metal throughout its length, said rods beingprovided at one end with enlarged portions bent semi-cylindric in form ,to provide a split bearing,'the bearing of one of said rods beingjournaled on 110 said crank, there being provided an aperture inthe shank portion of said rod adjacent to said bearing,` andthe' split bearing of the other of said rods being journaled on the bearing of the first mentioned rod and extending through said aperture thereof, and means ,for pivotally connecting the opposite ends ofsaid rod. with said pistons.

4,'In a device of the character described, the `combination with pistons mounted in cylinders arranged at an angle to each other, and a crank, of connecting rods connecting said crank and pistons and'formed from blanks cut from sheet metal, each of said blanks being folded upon itself to provide a double thickness of metal throughout its length, one of said blanks being provided at one end with enlargedportions bent semicylindric in form to provide-a split bearing adapted to be journaled .on said crank and 13o provided with an aperture adjacent to said bearing, the other of said rods belng provided with a bearing at its end journaled on and intermediate the ends of the Vbearing of the first mentioned rod and extending through said aperture thereof, a strap formed from a blank of sheet metal bent to form two cylindric portions adapted to surround the end portions of the bearing of the first mentioned rod at either side of the bearing of said last mentioned rod and end portions secured to the rod adjacent to said aperture, and means for pivotally connecting the opposite ends of said rod with said pistons.

5. In a device of the character described, the combination with pistons mounted in cylinders arranged at an angle to each other, and a crank, of connecting rods connecting said crank and pistons, and formed of a double thickness of sheet metal, oneof said rods being provided at one end with enlarged portions bent cylindric vin form to provide a bearing adapted to beijournaied on said crank and provided with an aperture adjacent to said bearing, the end portions of the other of said rods being formed to provide a bearing of less width than that of the rst mentioned rod, thev same being journaled on the bearing of the first mentioned rod throughout a portion of its Width land extending through said aperture thereof, a strap of sheet metal surrounding the split bearing of said last mentioned rod and fastened at the ends to the rod adjacent to said bearing, and a strap surrounding the free portions of the bearing of Said vfirst mentioned rod and fastened to the same adjacent to the bearing thereof.

.6. In a device of the character described, the combination With pistons mounted in cylinders arranged at an angle to each other, and a crank, of connecting rods connecting said crank and pistons and formed from blanks cut from sheet metal, each of said blanks-being folded upon itself to provide l a double thickness of metal throughout its length, said rods being provided at one end with enlarged portions bent cylindric 'in form to provide a split bearing, 'the bearing of one of said rods being adapted t'o be journaled on said crank, there being provided an aperture in said rod adjacent to said bearing, the split bearing of the other of said rods being journaled on the bearing of the first mentioned rod and extending through said aperture thereof, a strap of sheet metal surrounding the split bearing of' said last mentioned rod and fastened at the ends to the rod adjacent to jsaid bearing, and a strap surrounding the end portions of the bearing of said first mentioned rod and fastened to the same adjacent tol the bearing thereof.

7 In a device of the character described,

the combination with pistons mounted in cylinders arranged at an angle to each other, and a crank, of connecting rods formed of a double thickness of sheet metal, each rod provided at one of its ends with a split bearing integral therewith, the bearing of one rod being journaled on said crank, there being provided an aperture in said rod adjacent to said bearing, a strap formed from a blank of sheet metal having open cylindric portions spaced apart and parallel end ianges extending from the open ends of said cylindric portions, said cylindric portions surrounding the end portions of said split bearing of said last mentioned rod, and the end flanges being secured to the rod adjacent to said bearing and in contact with the opposite ends thereof, said flanges being provided with apertures registering with said aperture in said rod, the split bearing of the other of said rods surrounding the bearing of said first mentioned rod intermediate the cylindric portions of the strap thereof and extending through said apertures, a strap surrounding said bearing and fastened to said rod adjacent to the bearing thereof, and means for pivotally connecting the opposite ends kof said rods to said pistons.

.8. The combination with a piston, of a connecting rod formed of a double thickness of sheet metal and provided at one end with a cylindric portion extending ltransversely of said' rod and forming a journal integral with said rod, and a strap provided With a yoke surrounding an end of said journal and flanges rigidly connected to said piston.

9. The combination with a piston, of a sheet metal bent transversely upon itself to provide a double thickness of metal throughout its length, and provided at its end with a tubular portion extending transversely of-said rod and forming an integral cross-pin, a bearing block having a concave seat in which said cross-pin is journ-aled, said bearing block being interposed between said rod and the piston, and straps provided with yokes surrounding the ends of said cross-pin and flanges rigidly connected to said piston.

l0. The combination with a piston, of a connecting rod formed of a double thickness of sheet-metal and provided at its end with a cylindric portion extending transversely of said rod and forming an integral cross-pin, and means for pivotally connecting said rod to said piston, comprising straps formed from a blank of sheet metal bent to provide semi-cylindric yokes sur- -rounding the ends of said cross-pin, and

- connecting rod formed from a blank of Lacasse connecting rod formed of a double thickness of sheet metal vand provided at its end with a cylindric portion extending transversely of said vrod and forming an integral cross-pin, and means for pivotally connecting said rod to said piston, comprising al strap formed from a blank of sheet metal having a central aperture and bent to provide semi-cylindric yokes extendingftrans- `versely from said aperture, said yoke portions surrounding the ends 4of said crosspin and said rod extending through said aperture, the flanges of said strap having flat contact With the head of said piston and being rigidly 'attached thereto.

12. The combination With a piston, of a connecting rod formed from a blank of sheet metal bent upon itself to provide a double thickness of metal throughout its length and at its end With a hollow cylindric portion extending transversely of said rod and forming an integral cross-pin, and means for pivotally connecting said rod to said piston, comprising a strap formed from a blank of sheet met-al bent to provide semi-cylindric yokes extending transversely from said aperture, said strap beingcut into tWo parts" along a longitudinal central line, each part being applied to the opposite ends of said cross-pin with the yoke portions surrounding said end portions of the pin, and the flange portion of each part in flat contact with the head of said piston and rigidly secured thereto.

13. rlhe combination With apiston, of a connecting rod formed from a blank of sheet metal bent longitudinally upon itself to provide a double thickness of metal throughout its length and at its end with a hollowv cylindric portion extending transversely of said rod and forming an integral cross-pin,

a bearing blockhaving a concave seat 1n Which said cross-pin is journaled,` said block being greater in length than sald crosspin, a strap formed of sheet metal bent to form semi-cylindric yoke portions surrounding the end portions of said yoke member and said bearing block, and flange portions rigidly secured to said piston, said strap being provided with an aperture through which said rod extends, the same being greater in Width than the rod, thereby permitting transverse movement of said rod.

14. The combination With a piston and a crank, of a connecting rod formed of a double thickness of sheet metal and having at one end a transverse cylindric cross-pin formed integral therewith adapted to be pivotally connected to saidpiston, and at the other end a tubular bearing adapted to be journaled 'on said crank, and straps formed from blanks of sheet metal bent to surround saidy cross-pin and said bea-ring` and to be connected to sald piston and connecting rod, respectively.

15. rlhe combination with a piston and crank, of a connecting rod formed fromf a blank cut from sheet metal and provided With an enlarged central portion, said vblank being bent transversely upon itself at its central portion to provide a double thickness of metal, said central portion being formed cylindric to provide an integral cross-pin, and the free ends of said rod being formed semicylindric to provide a split bearing at the l opposite end of said rod adapted to be journaled on said crank,and straps formed from blanks cut from sheet metal and bent to surcylindric cross pin, a concave block on which said cross pin is journaled, and a strap surrounding said cross pin and block and rigidly secured to said piston.

lin testimony that I claim the foregoing as my invention I alix my signature, in the presence of two witnesses, this 25th day of Sept., A. D. 1915'. l

AXEL LEVEDAHL. Witnesses:

llvER A. HANssEN, FRANK S. RHoADs. 

